Linear roller guide

ABSTRACT

A first invention of the subject application aims to smoothly circulate the rollers by integrally molding at least one member of the roller returning passage, the roller end surface guide wall and the direction changing portion with the block body. 
     Namely, at least one member of the roller returning passage forming member  91  for forming the roller returning passage  9 , the roller end surface guide wall  13  and the direction changing passage inner periphery portion forming member  12  for forming the direction changing passage inner periphery portion  10   b  is integrally molded by inserting the block body into a molding die. 
     A second invention of the subject application aims to realize a smooth circulation and movement of the rollers, and to prevent the running-out of the roller chain during the circulation of the roller.

TECHNICAL FIELD

The present invention relates to a linear motion guide device, and moreparticularly, to a linear roller guide device using rollers as rollingelements.

BACKGROUND ART

The conventional linear roller guide device of this type generally has astructure in which a movable block is movably supported on a track railthrough a number of rollers. The guide device using rollers has anadvantage of high rigidity and high load bearing ability in comparisonwith the guide device using balls. The movable block comprises a blockbody and side covers to be attached to both end portions of the blockbody. The block body is provided with a roller rolling surface and aroller returning passage for endlessly circulating a roller row, and theside cover is provided with a direction changing passage for connectingthe roller rolling surface side to the roller returning passage.

Both sides of the roller rolling surface of the movable member areprovided with a roller end surface guide wall for guiding an end surfaceof the roller, and each of the roller returning passage and thedirection changing passage is also provided with a guide wall which isformed to be continuous to the roller end surface guide wall. wherebythe end surfaces of the roller are guided in entire circulating passageso as to orderly circulate the rollers.

Conventionally, as to structural members such as the roller returningpassage, the side cover and the roller end surface guide wall or thelike, an attempt to reduce a manufacturing cost has been made byemploying resin moldings as the structural members.

However, the above conventional linear roller guide devices entaildrawbacks as described hereunder:

{circle around (1+L )} The manufacturing process is complicated.

That is, each of the resin molded members is a molded member which isformed separately from the block body, so that a process of assemblingthe respective resin molded members is required after separately formingthe respective members.

{circle around (2+L )} The circulating defects of the roller at theroller rolling surface are liable to occur.

Namely, when assembled the resin molded members, irregularities areliable to occur at a connecting portion between the roller returningpassage and the direction changing passage, and at a connecting portionbetween the roller rolling surface and the direction changing passage,so that there may be posed a problem, for example, that a smoothcirculation of the rollers is obstructed and a problem of generation ofan abnormal noise.

{circle around (3+L )} The circulating defects of the roller at theroller end surface are liable to occur.

In particular, in case of the roller, it is required to prevent skew ofthe roller (i.e. blurring of a rotational axis of the roller). In orderto prevent the skew, it is required to guide the end surface of theroller not only in a range of a loaded area of the roller rollingsurface but also in all around of an endlessly circulating passageranging from the direction changing passage to the non-loaded area ofthe roller returning passage.

FIG. 15(a) shows a state that the roller 100 changes a rolling directionthereof form an unloaded area α to a loaded area β of the directionchanging passage. At the time of direction changing of the roller 100,for example, as schematically shown in FIGS. 15(b) and 15(c), when theroller 100 moves from the loaded area α, and then enters into the loadedarea β in a skewed state, one end portion of the roller 100 a of theroller 100 will firstly collide against the roller rolling surface 101in the loaded area, so that the smooth movement of the roller 100 isobstructed. In addition, an edge load may occur at the end portion 100 aof the roller 100 entering into the loaded area β, so that the roller100 per se and the roller rolling surface 101 are damaged thereby todeteriorate durability of the guide device. Further, vibration of theroller and changes in rolling resistance during the circulation of therollers will occur thereby to obstruct the smooth circulation of therollers.

In order to prevent such problems, hitherto, the end surface of theroller is formed so as to be guided by the roller end surface guide wallprovided at both sides of the roller rolling surface and passage wallsprovided at the direction changing passage and the roller returningpassage. However, since the guide system is formed by connecting thediscontinuous roller end surface guide wall, direction changing passageand roller returning passage, a sticking of the roller is liable tooccur due to non-uniformity in a width of the respective passages andthe irregularities of the connected portions thereby to also obstructthe smooth circulation of the rollers.

{circle around (4+L )} A falling-out of the roller is required to beprevented.

On the other hand, hitherto, in order to prevent the roller from fallingout from the movable block when the movable block is detached from thetrack rail, there is a well known structure in which a chamfered portionis provided at end portion of the roller and an engaging projection withwhich the chamfered portion is engaged is provided at the roller endsurface guide wall formed along the roller rolling surface.

However, in case of such roller retaining system, when the engagingprojection interferes with the roller during the circulation of theroller, the smooth circulation of the roller is obstructed. Therefore,when assembling the guide device, it is required to provide a small gapor clearance between the roller and the engaging projection so as not tointerfere the engaging projection with the roller. However, it wasdifficult to provide the engaging projection to an accurate position.

In addition, the chamfered portion is required to be provided, so thatan effective length for bearing the load is disadvantageously shortenedin a length corresponding to the length of the chamfered portion,thereby to lower the load bearing ability.

On the other hand, there is also another well-known roller retainingsystem in which a number of rollers are retained in form of a chain bylinking the rollers in a roller chain. However, in the case of suchrollers retained in the roller chain, a problem of a running-out of theroller chain will arise during the circulation of the rollers.Therefore, it is necessary to guide the roller chain along thepredetermined track. However, it was difficult to accurately guide theroller chain.

The first invention has been achieved for solving the problems describedabove, and an object of this invention is to provide a linear rollerguide device enabling to reduce the assembling processes, to accuratelyposition the structural members to a predetermined positions of theblock body, and to secure the smooth circulation of the rollers byintegrally forming at least one of the roller returning passage, rollerend surface guide wall and direction changing passage with the blockbody.

An object of the second invention is, in addition to the objectdescribed above, to provide a linear roller guide device enabling tosecurely prevent the roller chain from running-out during thecirculation of the rollers linked by the roller chain.

DISCLOSURE OF THE INVENTION

In order to achieve the afore-mentioned object, the first inventionprovides a linear roller guide device comprising a track rail and amovable block assembled to the track rail through a number of rollers,

the movable block comprising:

a roller rolling surface on which the rollers roll;

a block body having a roller returning passage corresponding to theroller rolling surface;

a direction changing passage inner periphery portion formed to both endsurfaces of the block body;

a pair of roller end surface guide walls formed to both sides of theroller rolling surface of the block body and adapted to guide both theend surfaces of the roller; and

side covers each having a direction changing passage outer peripheryportion for forming a direction changing passage by fitting the sidecover into the direction changing passage inner periphery portion formedto both end surfaces of the block body,

the track rail including a roller rolling surface extending in an axialdirection corresponding to the roller rolling surface of the block body,and

the rollers circulating in an endless circulating passage constituted bya loaded area between the roller rolling surface of the block body andthe roller rolling surface corresponding to the track rail, thedirection changing passage and the roller returning passage,

wherein at least one of a roller returning passage forming member forforming the roller returning passage, a roller end surface guide wallforming member for forming at least one of the paired roller end surfaceguide wall and a direction changing passage inner periphery portionforming member for forming the direction changing passage innerperiphery portion is formed as a molded body integrally formed with theblock body by inserting the block body into a molding die.

According to the structure described above, the assembling of the rollerend surface guide wall forming member, the roller returning passageforming member and the direction changing passage inner peripheryportion forming member is not required, thus eliminating the assemblingprocess for the members.

In addition, the roller end surface guide wall, the roller returningpassage and the direction changing passage inner periphery portion canbe formed at accurate positions with respect to the block body.

After the rollers are rolled from a starting end to a terminal end ofthe roller rolling surface of the block body, the rollers are rolled andmoved to the roller returning passage through the direction changingpassage, moved along the roller returning passage, and thereafter,supplied to the starting end side of the roller rolling surface throughthe direction changing passage formed at the other side of the rollerrolling surface.

When the direction changing passage inner periphery portion formingmember is integrally formed with the block body, it becomes possible toeliminate the irregularities to be formed at the connected portionbetween the roller rolling surface and the direction changing passageinner periphery portion. In addition, as to the roller returning passageforming member, when it is integrally formed with the block body, italso becomes possible to eliminate the irregularities to be formed atthe connected portion between the direction changing passage innerperiphery portion and the roller returning passage.

Further, in one aspect of this invention, the device may have astructure in which the roller returning passage and the directionchanging passage inner peripheral portion are provided with guide wallsfor guiding the end surface of the roller, the guide wall beingcontinuous to the roller end surface guide wall, and the rollerreturning passage, the roller end surface guide wall of at least one ofthe paired roller end surface guide walls and the direction changingpassage inner peripheral portion are integrally formed with the blockbody.

According to the structure described above, the roller end surface guidewalls of the roller returning passage and the direction changing passagein an unloaded area and the roller end surface guide wall to be formedalong the roller rolling surface in loaded area can be continuouslymolded, so that the irregularities are not formed at the connectedportions in all around the endless circulating passage, thus enables theend surface of the roller to smoothly move.

In addition, the gap or clearance between the guide wall and the rollerend surface can be formed with high accuracy in all around the endlesscirculating passage, so that the generation of the skew of the rollercan be securely prevented.

In another aspect of this invention, the device may have a structure inwhich a chamfered portion is provided at least one end portion of theroller and an engaging projection with which the chamfered portion ofthe roller is engaged is provided at the roller end surface guide wallintegrally molded with the block body so as to prevent the roller fromfalling out.

As described above, when such engaging projection is provided at theroller end surface guide wall to be integrally molded with the blockbody, the engaging projection can be accurately positioned with respectto the block body, so that the falling-out of the roller can be securelyprevented even if the bearing block is detached from the track rail. Inaddition, there is not the slightest fear of interference of the blockbody with the roller during the circulation of the roller.

The guide device has a structure having four rows of rollers in total inwhich a pair of right and left rows of rollers are disposed to berollable between the upper surface of the track rail and a lower surfaceof a horizontal portion of the block body and other two rows of therollers each is disposed between the right and left side surfaces of thetrack rail and an inside surfaces of a suspending portion of the blockbody, respectively.

In this case, it is preferable that a contact angle line constituted bya line connecting two contact points of the roller disposed between thecorresponding roller rolling surfaces formed to the upper surface of thetrack rail and the horizontal portion of the block body is set tovertically extend with an inclination angle of about with respect to ahorizontal line, while a contact angle line of the roller disposedbetween the corresponding roller rolling surfaces formed to the rightand left side surfaces of the track rail and the inside surfaces of thesuspending portion of the block body is set to obliquely extenddownwards and is formed so as to incline with an inclination angle of30° with respect to a horizontal line.

In still another aspect of this invention, the guide device has astructure having four rows of rollers in total in which two rows ofrollers are vertically disposed to be rollable between a right sidesurface of the track rail and a right inside surface of the suspendingportion of the block body, and vertically disposed to be rollablebetween a left side surface of the track rail and a left inside surfaceof the suspending portion of the block body, respectively.

Among the two rows of the rollers arranged vertically at upper and lowerportions, it is preferable that the upper row of rollers is formed sothat a contact angle line of the roller is set to obliquely extendupwards from a side of the track rail to sides of the right and leftsuspending portions of the block body, and is formed so as to inclinewith an inclination angle of almost 45° with respect to a horizontalline, while the lower row of rollers is formed so that a contact angleline of the roller is set to obliquely extend downwards, and is formedso as to incline with an inclination angle of almost 45°, or that theupper row of rollers is formed so that a contact angle line of theroller is set to obliquely extend downwards from a side of the trackrail to sides of the right and left suspending portions of the blockbody, and is formed so as to incline with an inclination angle of almost45° with respect to a horizontal line, while the lower row of rollers isformed so that a contact angle line of the roller is set to obliquelyextend downwards, and is formed so as to incline with an inclinationangle of almost 45°.

In particular, at a time of an insert molding, when a block supportingportion corresponding to the roller rolling surface of the block body isprovided to an inner periphery of a molding die and the roller rollingsurface is contacted to the block supporting portion, the block body canbe effectively positioned in the molding die.

According to such structure, a pair of right and left roller rollinggrooves (surfaces) of the block body will contact to the blocksupporting portion. As a result, the block body is supported by thepaired right and left block supporting portions so that the block bodyis clamped from every four directions and supported by four points.Therefore, even if an injection pressure of a molding material isapplied to the block body from every directions, the block body can beheld unmoved, and the burr is not formed at a portion between the rollerrolling surface and the block supporting portion.

In a second invention, there is provided a linear roller guide devicecomprising a track rail and a movable block assembled to the track railthrough a number of rollers,

the movable block comprising:

a block body having a roller rolling surface and a roller returningpassage corresponding to the roller rolling surface;

a direction changing passage inner periphery portion formed to both endsurfaces of the block body; and

side covers each having a direction changing passage outer peripheryportion for forming a direction changing passage by fitting the sidecover into the direction changing passage inner periphery portion formedat both end surfaces of the block body,

the track rail including a roller rolling surface extending in an axialdirection corresponding to the roller rolling surface of the block body,

the rollers circulating in an endless circulating passage constituted bya loaded area between the roller rolling surface of the block body andthe roller rolling surface corresponding to the track rail, thedirection changing passage and the roller returning passage, and therollers are linked to each other by a roller chain inserted to bemovable in the endless circulating passage,

wherein the roller returning passage and the direction changing passageinner periphery guide portion are provided with a roller chain guideportion for guiding a track of the roller chain onto a predeterminedtrack,

wherein at least one of the roller returning passage forming member forforming the roller returning passage and the direction changing passageinner periphery portion forming member for forming the directionchanging passage inner periphery portion is integrally molded byinserting the block body into a molding die.

According to the structure described above, the rollers can be smoothlyrolled and moved in the endless circulating passage while being kept ina state where center axes of the respective rollers are retained inparallel to each other and intervals of adjacent rollers are retained ina predetermined distance, thus enabling to prevent the skew-generation.

In addition, the roller chain is guided onto the predetermined track bythe roller chain guide portions formed to the roller returning passageand the direction changing passage, and the rollers shall be accuratelyguided by the roller chain guided by the roller chain guide portion.Further, a run-out of the roller chain can be prevented by the rollerchain guide portion.

In addition, when the roller returning passage forming member forforming the roller returning passage and the direction changing passageinner periphery portion forming member for forming the directionchanging passage inner periphery portion to which the roller chain guideportions are formed are integrally molded with the block body, theroller chain guide portions can be formed on accurate positions of thetrack.

In addition, when the direction changing passage inner periphery portionforming member is integrally formed with the block body, it becomespossible to eliminate the irregularities to be formed at the connectedportion between the roller rolling surface and the direction changingpassage inner periphery portion. Further, as to the roller returningpassage, when it is integrally formed with the block body, it alsobecomes possible to eliminate the irregularities to be formed at theconnected portion between the direction changing passage inner peripheryportion and the roller returning passage. As a result, the rollers canbe further smoothly circulated and moved in cooperation with the guidingfunction of the roller chain.

Furthermore, when the roller chain is formed so as to have an endlessstructure and is provided with a falling-out preventing portion for therollers, the falling-out of the rollers can be prevented by the rollerchain even if the movable block is detached from the track rail.

Further, the roller chain is preferably provided with a guide projectingportion so as to project from the end surface of the roller in an axialdirection of the roller, while the roller returning passage and thedirection changing passage inner peripheral portion are preferablyprovided with guide grooves with which the guide projecting portion isengaged. In addition, at least one side of the roller rolling surfacesformed to the block body is preferably provided with a guide wall havingthe guide groove extending in parallel to the roller rolling surface forguiding the guide projecting portion in parallel to the roller rollingsurface. As to this guide wall, it is also preferable to integrally moldthe guide wall with the block body by using an insert molding method andto continuously form the guide groove to the roller returning passage,the direction changing passage inner periphery portion and the guidewall so that the guide groove ranges to all around the endlesscirculating passage.

According to the structure described above, when the roller chain iscirculated and moved, the guide projecting portion is engaged with theguide groove formed to the roller returning passage and the directionchanging passage inner peripheral portion, so that the run-out of theroller chain is suppressed. As a result, the rollers can be rolled andmoved in orderly arranged state in all around the endless circulatingpassage.

In addition, in a case where the roller chain is formed in astriped-shape having no connected portion at both ends thereof, when themovable block is detached from the track rail, the guide projectingportion is engaged with the guide groove, thus enabling to prevent asagging or slack of an end portion of the roller chain. Further, also ina case of the roller chain having an endless structure, the sagging orslack of an intermediate portion of the roller chain can be prevented.

In still another aspect of this invention, the roller chain comprisesspacer portions disposed between the adjacent rollers and connectingportions for connecting the respective spacer portions, and the guideprojecting portion is provided to the connecting portion.

Accordingly, each of the rollers is arranged and circulated in a statewhere the rollers are retained by the spacer portions form back andforth in the arranging direction thereof.

Further, when a falling-out preventing portion for the roller isprovided to the spacer portion so as to prevent the falling-out of theroller from back and forth of the roller, it becomes unnecessary tochamfer the end portion of the roller, so that an effective length ofthe roller for bearing the load can be increased.

Furthermore, since only the spacer portion is disposed between theadjacent rollers, a pitch of the rollers can be formed as small aspossible, so that a number of the rollers to be disposed per unit lengthfor bearing the load can be increased as many as possible, thusimproving the load bearing ability of the roller.

In still another aspect of this invention, the connecting member and thespacer portion disposed between the adjacent rollers are formed as resinmoldings, the roller is formed to have a hollow portion, and the rolleris retained by inserting a resin portion into the hollow portion of theroller.

According to the structure described above, the falling-out of theroller can be surely prevented and a degree of parallelization betweenthe adjacent rollers can be accurately maintained.

In addition, the roller may be retained in such a manner that a recessedportion is formed to both end portions of the roller and the resinportion is inserted into the recessed portion or in a manner that agrooved portion is formed to a center peripheral portion of the rollerand the resin portion is fitted into the grooved portion.

When the roller chain moves at portion between the roller rollingsurfaces and the unloaded roller rolling passage, the roller chain takesa linear shape. In contrast, when the roller chain moves in thedirection changing passage, the roller chain is deformed fromlinear-shape to a curved-shape. As a result, the roller chain isrepeatedly deformed in accordance with the movement of the movableblock.

In view of this point, it is preferable to reinforce the roller chain byinserting a wire or thin plate into the connecting member.

In the guide device of the present invention, the number of rollers andarrangement thereof are optional. However, the following arrangementsare more effective.

That is, the guide device may have a structure having four rows ofrollers in total in which a pair of right and left rows of rollers aredisposed to be rollable between the upper surface of the track rail anda lower surface of a horizontal portion of the block body, and one rowof the roller is disposed between the right and left side surfaces ofthe track rail and inside surfaces of a suspending portion of the blockbody, respectively.

In this case, it is preferable that a contact angle line constituted bya line connecting two contact points of the roller disposed between thecorresponding to the roller rolling surfaces formed to the upper surfaceof the track rail and the horizontal portion of the block body is set tovertically extend with an inclination angle of about 90° with respect toa horizontal line, while a contact angle line of the roller disposedbetween the corresponding roller rolling surfaces formed to the rightand left side surfaces of the track rail and the inside surfaces of thesuspending portion of the block body is set to obliquely extenddownwards and is formed so as to incline with an inclination angle of30° with respect to a horizontal line.

In addition, the guide device may have a structure having four rows ofrollers in total in which two rows of rollers are vertically disposed atupper and lower portions to be rollable between a right side surface ofthe track rail and a right inside surface of the suspending portion ofthe block body, and vertically disposed to be rollable between a leftside surface of the track rail and a left inside surface of thesuspending portion of the block body, respectively.

Among the two rows of the rollers arranged vertically, it is preferablethat the upper row of rollers is formed so that a contact angle line ofthe roller is set to obliquely extend upwards from a side of the trackrail to sides of the right and left suspending portions of the blockbody and is formed so as to incline with an inclination angle of almost45° with respect to a horizontal line, while the lower row of rollers isformed so that a contact angle line of the roller is set to obliquelyextend downwards, and is formed so as to incline with an inclinationangle of almost 45°; or that the upper row of rollers is formed so thata contact angle line of the roller is set to obliquely extend downwardsfrom a side of the track rail to sides of the right and left suspendingportions of the block body and is formed so as to incline with aninclination angle of almost 45° with respect to a horizontal line, whilethe lower row of rollers is formed so that a contact angle line of theroller is set to obliquely extend downwards and is formed so as toincline with an inclination angle of almost 45°.

In particular, at a time of an insert molding, when a block supportingportion corresponding to the roller rolling surface of the block body isprovided to an inner periphery of a molding die and the roller rollingsurface is contacted to the block supporting portion, the block body canbe effectively positioned in the molding die.

According to such structure, a pair of right and left roller rollinggrooves (surfaces) of the block body will contact to the blocksupporting portion. As a result, the block body is supported by thepaired right and left block supporting portions so that the block bodyis clamped from every four directions and supported by four points.Therefore, even if an injection pressure of a molding material isapplied to the block body from every directions, the block body can beheld unmoved, and the burr is not formed at a portion between the rollerrolling surface and the block supporting portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing one embodiment of a linear roller guide deviceaccording to the first invention.

FIG. 2 is also a view showing one embodiment of the first invention.

FIG. 3 is a view showing various modifications of the roller end surfaceguide walls and roller retaining s structures for the linear rollerguide device shown in FIG. 1.

FIG. 4 is an explanatory view showing a molding method of a movableblock for the linear roller guide device shown in FIG. 1.

FIG. 5 is a view showing a modification of a roller returning passageforming member shown in FIG. 1.

FIG. 6 is a view showing another roller contact angle structure of theembodiment according to the first invention.

FIG. 7 is a view showing still another roller contact angle structuresof the embodiment according to the first invention in which

FIG. 7(a) is a cross sectional view of the linear roller guide deviceand

FIG. 7(b) is a cross sectional view showing a direction changingpassage.

FIG. 8 is a view showing one embodiment of a linear roller guide deviceaccording to the second invention in which a roller chain is used.

FIG. 9 is a view showing structures of chain guide portions and rollerchains in FIG. 8.

FIG. 10 is a view showing another embodiment of the roller chain shownin FIG. 9.

FIG. 11 is a view showing a modification of the roller end surface guidewall for the linear roller guide device shown in FIG. 8 and anotherstructure of the roller returning passage forming member.

FIG. 12 is a view showing a molding method of a movable block shown inFIG. 8.

FIG. 13 is a view showing another roller contact angle structure of theembodiment according to the second invention.

FIG. 14 is a view showing another roller contact angle structure of theembodiment according to the second invention.

FIG. 15 is an explanatory view showing a state where a roller-skewoccurs in a conventional linear roller guide device.

BEST MODE FOR EMBODYING THE INVENTION

[The First Invention]

Hereunder, the first invention will be explained with reference to theaccompanying drawings.

FIGS. 1 and 2 are views showing an embodiment of a linear roller guidedevice according to the first invention. The linear roller guide device1 comprises a track rail 2, four rows of rollers 3 in total of which tworows of rollers are disposed to an upper side surface of the track rail2 and one row of rollers is disposed to both right and left sidesurfaces of the track rail 2 respectively, and a movable block 4assembled to be movable through the four rows of rollers 3.

The track rail 2 is an elongated member formed to have a rectangularshape in section, an upper portion of both the side surfaces of thetrack rail being formed to have tapered surfaces which gradually expandoutwardly in upward direction, and each of the right and left taperedsurfaces is provided with one row of roller rolling surface 5,respectively. In addition, the upper surface of the track rail 2 isformed to be a plain surface of which both right and left end portionsare provided with one row of roller rolling surface 6, respectively,i.e., two rows of the roller rolling surfaces 6 in total.

The movable block 4 comprises a block body 40 formed of metal, and sidecovers 11 to be attached to both end surfaces of the block body 40.

The block body 40 has a U-shaped cross section and high rigidity, andcomprises a horizontal portion 41 opposing to the upper surface of thetrack rail 2, a pair of suspending portions 42 and 42 suspending fromthe right and left end portions of the horizontal portion 41 so as toclamp both the right and left side surfaces of the track rail 2. A lowersurface of the horizontal portion 41 is provided with a pair of rollerrolling surfaces 7, 7 corresponding to the paired roller rollingsurfaces 6, 6 formed to the upper surface of the track rail 2, whileeach of inner side surfaces of the right and left suspending portions42, 42 is provided with a roller rolling surface 8 corresponding to therespective roller rolling surfaces 5, 5 formed to the right and leftside surfaces of the track rail 2.

A number of rollers 3 are disposed between four pairs of roller rollingsurfaces 5, 8; 6, 7, corresponding to each other, that are formed toopposing surfaces between the track rail 2 and the movable block 4,whereby roller rows for bearing a load to be applied to portions betweenthe track rail 2 and the movable block 4 are assembled. A predeterminedpre-load is applied to respective rollers 3. The roller 3 is formed as acylindrical roller. However, as shown in FIG. 3(d), a barrel-shapedroller having a circular-arc shaped cross section in axial direction canbe also available as the roller 3.

Each of the rollers 3 linearly contacts to the roller rolling surfaces5, 8; 6, 7. A contact angle line L1 constituted by a line connecting twocontact portions of the roller disposed between the corresponding to theroller rolling surfaces 5, 8; 6, 7 formed to the upper surface of thetrack rail 2 and the horizontal portion 41 of the block body 40 is setto vertically extend with an inclination angle of about 90° with respectto a horizontal line passing through a center of the roller 3, while acontact angle line of the roller 3 disposed between the corresponding tothe roller rolling surfaces formed to the right and left side surfacesof the track rail 2 and the inside surfaces of the right and leftsuspending portions 42, 42 of the block body 40 is set to obliquelyextend toward a center of the track rail 2 and is formed so as toupwardly incline with a predetermined angle of α with respect to ahorizontal line H passing through a center of the roller 3, thereby toform a structure in which both the right and left corner portions 22, 22of an upper portion of the track rail 2 are clamped by the two rows ofrollers 3, 3 disposed to the right and left sides of the track rail 2and by the two rows of rollers 3, 3 disposed to the upper surface sideof the track rail 2. In the embodiment shown in Figure, the angle of αis set to about 30°.

The block body 40 is provided with four rows of the roller returningpassages 9 for circulating and guiding the four rows of rollers 3. Theroller returning passage 9 linearly extend in parallel to the respectiveroller rolling surfaces 5, 6 formed to the block body 40. Two rows ofthe roller returning passages 9 are provided to the horizontal portion41, while two rows of the roller returning passages 9 are respectivelyprovided to the right and left suspending portions of the block body 40.The roller returning passage 9 is formed from a roller returning passageforming member 91 composed of resin.

The roller returning passage forming member 91 is integrally bonded toan inner peripheral portion of a penetration bore 43 penetrating throughthe horizontal portion 41 and the suspending portion 42 of the blockbody 40. An outer peripheral shape of the roller returning passageforming member 91 is formed to have a cylindrical shape which conformsto an inner peripheral shape of the penetration bore 43. The innerperiphery of the roller returning passage forming member 91 is providedwith a roller returning passage 9 having a rectangular cross section forguiding the roller 3.

The roller returning passage 9 comprises a pair of unloaded roller guidesurfaces 9 a, 9 b extending in parallel to each other for guiding acylindrical outer periphery surface of the roller 3, and a pair ofunloaded roller end surface guide surfaces 9 c, 9 c extending inparallel to each other for guiding end surfaces of the roller 3.

A gap or clearance between the paired unloaded roller guide surfaces 9a, 9 b is set to slightly larger than a diameter of the roller 3 so asto form a small gap therebetween, while a gap or clearance between thepaired unloaded roller end surface guide surfaces 9 c, 9 c is set toslightly larger than a length of the roller 3 so as to form a small gaptherebetween, thus resulting in a structure enabling to smoothly movethe rollers 3 (see FIG, 3(e)).

FIG. 5 shows another embodiment of a roller returning passage formingmember 92 to be formed to the suspending portion 42 of the block body40. Namely, the roller returning passage forming member 92 is integrallybonded to a recessed portion 44 formed to a lower end portion of theright and left suspending portions 42 of the block body 40. The rollerreturning passage forming member 91 is integrally connected to a thirdloaded roller end surface guide wall forming member 143 provided to theinner peripheral side of the suspending portion 42.

According to the structure described above, the block body 40 isrequired to be provided with only two penetration bores 43 to be formedto the horizontal portion 41, thus enabling to simplify themanufacturing of the device.

In addition, as shown in FIGS. 1(b), (c) and 2, both end portions of theblock body 40 are provided with side covers 11 constituting a directionchanging passage 10 for changing the rolling direction of the roller 3to the roller returning passage 9, the roller 3 being disposed betweenthe loaded roller rolling surfaces 5, 8; 6, 7 formed to the track rail 2and the block body 40.

The direction changing passage 10 is formed to be a pipe having aU-shape. The side cover 11 is formed with only a direction changingpassage inner periphery portion 10 a of the direction changing passage10. while a direction changing passage inner periphery portion formingmember 12 is integrally bonded to both end portions of the block body40.

This direction changing passage 10 has a rectangular shaped crosssection, and both side portions of the direction changing passage outerperiphery portion 10 a and the inner periphery portion 10 b for guidingthe outer periphery surface of the roller 3 are provided with directionchanging roller end surface guide walls 10 c, 10 c for guiding the endsurfaces of the roller 3. This direction changing roller end surfaceguide walls 10 c together with the direction changing passage innerperiphery portion 10 b are formed to the direction changing passageinner periphery portion forming member 12. Then, when the side cover 11formed with the direction changing passage outer periphery portion 10 ais fitted into the end surface of the block body 40 formed with thedirection changing passage inner periphery portion 10 b and thedirection changing roller end surface guide walls 10 c, the directionchanging passage 10 having a U pipe shape is formed.

In this regard, the direction changing roller end surface guide walls 10c, 10 c together with the direction changing passage outer peripheryportion 10 a may be provided to the side cover 11. In another way, onedirection changing roller end surface guide wall 10 c together with thedirection changing passage inner periphery portion 10 b may be providedto a side of the direction changing passage inner periphery portionforming member 12, while the other direction changing roller end surfaceguide walls 10 c together with the direction changing passage outerperiphery portion 10 a may be provided to the side cover 11.

In still another way, the direction changing roller end surface guidewall 10 c is divided into two portions i.e. an inner periphery sideportion and an outer periphery side portion, and then, the outerperiphery side portion may be formed to the side cover 11, while theinner periphery side portion may be provided to the direction changingpassage inner periphery portion forming member 12.

Further, as shown in FIG. 1(a). along the respective four rows of rollerrolling surfaces 7, 8 of the block body 40, there is provided with aloaded roller end surface guide wall 13 for guiding the end surfaces ofthe roller in the loaded area. In order to form the loaded roller endsurface guide wall 13, the block body 40 comprises a first end surfaceguide wall forming member 141 to be integrally bonded to a lower surfaceof the horizontal portion 40, right and left second end surface guidewall forming members 142 to be integrally bonded to recessed cornerportions between the horizontal portion 41 and the right and leftsuspending portions 42, and right and left third end surface guide wallforming members 143 to be integrally bonded to a lower portion of innerside surface of the right and left suspending portions 42.

The both end portions of the first end surface guide wall forming member141 and an upper end portion of the second end surface guide wallforming members 142 are provided with loaded roller end surface guidewalls 13, 13; 13, 13 for guiding the end surfaces of the roller 3rolling on the roller rolling surfaces 7, 7 formed to the lower surfaceof the horizontal portion 41 of the block body 40.

In addition, the lower end portions of the right and left second endsurface guide wall forming member 142 and an upper end portion of thethird end surface guide wall forming members 143 are provided withloaded roller end surface guide walls 13, 13; 13, 13 for guiding the endsurfaces of the roller 3 rolling on the roller rolling surfaces 8, 8formed to the suspending portion 42 of the block body 40.

A gap or clearance between the paired loaded roller end surface guidewalls 13, 13 is set to slightly larger than a length of the roller 3 soas to form a small gap between the end surface of the roller 3 and theguide wall 13.

Further, a first seal member 15 for sealing the gap formed between thehorizontal portion 41 of the block body 40 and the upper surface of thetrack rail 2 is attached to the first end surface guide wall formingmember 141, while a second seal member 16 for sealing the gap formedbetween the suspending portion 42 of the block body 40 and the right andleft side surfaces of the track rail 2 is attached to the third endsurface guide wall forming member 143.

In this embodiment, the loaded roller end surface guide walls 13 forguiding both end surfaces of the roller 3 is formed by the first tothird end surface guide wall forming members 141-143 that are allcomposed of resin.

However, as shown in FIG. 3(a), the loaded roller end surface guidewalls 13 for guiding one end surface of the roller 3 may be formed bythe block body 40 per se, while the loaded roller end surface guide wall13 for guiding the other end surface of the roller 3 may be formed bythe loaded roller end surface guide wall forming member 14. In anotherway, as shown in FIG. 3(f), both side of the loaded roller end surfaceguide walls 13 can be also formed by the block body 40.

In this first embodiment, all of the roller returning passage formingmember 91, the roller end surface guide wall forming members 141-143 andthe direction changing passage inner periphery portion forming member 12are formed by integrally molding with the movable block.

Accordingly, the unloaded roller guide surfaces 9 a, 9 b of the rollerreturning passage 9 and both the inner and outer periphery portions 10a, 10 b of the direction changing passage can be continuously andintegrally molded. Further, the direction changing passage innerperiphery portion 10 b and the roller rolling surfaces 7, 8 in theloaded area can be also integrally molded.

In addition, the roller end surface guide wall 9 c of the rollerreturning passage 9, the direction changing roller end surface guidewall 10 c of the direction changing passage 10 and the loaded arearoller end surface guide wall 13 are continuously formed by beingintegrally molded, so that the roller end surface guide wall can becontinuously formed in all around the endless circulating passage.

According to the linear roller guide device of this invention, theassembling of the loaded roller end surface guide wall forming member14, the roller returning passage forming member 91 and the directionchanging passage inner periphery portion forming member 12 is notrequired, thus enabling to omit the assembling process for the members.

In addition, the roller end surface guide wall 13, the roller returningpassage 9 and the direction changing passage inner periphery portion 10b can be provided at accurate positions with respect to the block body40.

As a result, after the rollers 3 are rolled from a starting end to aterminal end of the roller rolling surfaces 7, 8 in the loaded area ofthe block body 40, the rollers 3 are moved to the roller returningpassage 9 through the direction changing passage 10 then moved along theroller returning passage 9, and thereafter, supplied to the starting endside of the roller rolling surfaces 7, 8 through the direction changingpassage 10 formed at the other end of the roller rolling surfaces 7, 8,

When the direction changing passage inner periphery portion formingmember 12 is integrally formed with the block body 40, it becomespossible to eliminate the irregularities to be formed at the connectedportion between the roller rolling surfaces 7, 8 and the directionchanging passage inner periphery portion 10 b. In addition, as to alsothe roller returning passage forming member 91, when the member 91 isintegrally formed with the block body 40, it also becomes possible toeliminate the irregularities to be formed at the connected portionbetween the direction changing passage inner periphery portion 10 b andthe roller returning passage 9.

Further, when the roller returning passage forming member 91 and thedirection changing passage inner peripheral portion forming member 12are provided with unloaded roller end surface guide wall 9 c and thedirection changing roller end surface guide wall 10 c for guiding theend surface of the roller, the guide walls being continuous to theloaded roller end surface guide wall 13 and these roller end surfaceguide walls are integrally formed with the block body 40, the loadedroller end surface guide wall 13, the direction changing roller endsurface guide wall 10 c and the unloaded roller end surface guide wall 9c can be continuously molded in all around the endless circulatingpassage without forming the irregularities at the connected portions ofthe guide walls, thus enabling the end surface of the roller to smoothlymove.

In addition, the gaps or clearances between the the loaded roller endsurface guide wall 13, the direction changing roller end surface guidewall 10 c, the unloaded roller end surface guide wall 9 c and the rollerend surfaces can be accurately maintained to constant values, so thatthe gaps or clearances can be limited to a small value, and the skew ofthe roller 3 can be securely prevented.

In addition, as shown in FIGS. 3(b) and 3(c), the device may have astructure in which a chamfered portion 3 a is provided at least one endportion of the roller 3 while an engaging projection 13 a, with whichthe chamfered portion 3 a of the roller 3 is engaged, is provided at theloaded roller end surface guide wall 13 integrally molded with the blockbody 40 so as to prevent the roller 3 from falling out when the movableblock 4 is detached from the track rail 2. A small gap is formed betweenthe engaging projection 13 a and the roller 3 so that the engagingprojection 13 a would not interfere with the roller 3 when the rollers 3roll and move between the roller rolling surfaces 6, 7; 5, 8.

As described above, when the engaging projection 13 a is provided at theroller end surface guide wall 13 to be integrally molded with the blockbody 40, the engaging projection 13 a can be accurately positioned withrespect to the block body 10, and the gap between the engagingprojection 13 a and the chamfered portion 3 a of the roller 3 can beaccurately maintained to a constant value, whereby there is no fear ofinterference of the engaging projection 13 a with the roller during thecirculation of the roller 3.

The integrally molding of the roller returning passage forming member91, the direction changing passage inner peripheral portion formingmember 12 and the loaded roller end surface guide wall 13 with the blockbody 40 is performed in accordance with an insert molding methodcomprising the steps of disposing the block body 40 into a molding die15 on the basis of the roller rolling surfaces 7, 8 formed to the blockbody 40, forming cavities corresponding to the respective resin moldedportions to be formed between an inner wall of the molding die 15 andthe block body 40, and injecting a molding material into the respectivecavities to form the resin molded portions.

FIG. 4 is a schematic view showing the block body 40 and states wherethe molding dies 15 are clamped or opened at the time of the insertmolding. Namely, a fixed molding die 15 a is provided with blocksupporting portions 15 b to which the roller rolling surfaces 7, 7; 8, 8are fitted for positioning, while a movable molding die 15 c is providedwith pins 15 d for forming the roller returning passage.

The block supporting portions 15 b have plain shapes corresponding tothe roller rolling surfaces 7, 7; 8, 8 and linearly extend in parallelto each other. In this regard, FIGS. 4(b) and 4(c) show only acircumference of the roller returning passage 9 of a side of thesuspending portion 42.

Cavities 15 e for forming the roller returning passage forming member 91are provided to inside the penetration bores 43 formed in the horizontalportion 41 and the suspending portion 42 of the block body 40,respectively. Further, cavities 15 f-15 h for forming the first to thirdloaded roller end surface guide wall forming members 141-143 areprovided to inner periphery portions of the horizontal portion 41 andthe suspending portion 42. respectively. Furthermore, cavities 15 i forforming the direction changing passage inner periphery portion formingmembers 12 are provided to both front and back end portions of the blockbody 40, respectively.

In this embodiment, the paired right and left roller rolling surfaces 7,7: 8, 8 of the block body 40 are supported at four points by the blocksupporting portions 15 b of the molding die 15. As a result, the blockbody 40 can be supported unmoved by the block supporting portions 15 b,even if an injection pressure of a molding material is applied to theblock body 40 from every directions, whereby the roller returningpassage 9, the direction changing inner periphery portion 10 b and thefirst to third loaded roller end surface guide walls 131-133 can beaccurately formed at predetermined positions.

In addition, since the block body 40 is stably positioned in the moldingdie 15, the burr is not formed at portions between the roller rollingsurfaces 7, 7; 8, 8.

It is preferable that the block supporting portions 15 b closely contactto the roller rolling surfaces 7, 8. However, even the block supportingportions 15 b and the roller rolling surfaces 7, 8 are moved in a smalldistance due to a small gap formed therebetween, the small gap can beallowed as far as a dimension accuracy is within an allowable range andthe resin material would not penetrate through the gap.

[Modifications of Roller Contact Angles]

Though the explanation described above has been made by taking anexample of a case in which total four rows of rollers are disposedbetween corresponding portions i.e., the right and left two rows ofrollers being disposed between the upper surface of the track rail 2 andthe lower surface of the horizontal portion 41 of the block body 40while one row of rollers being disposed between the right and left sidesurfaces of the track rail 2 and the inner side surfaces of the rightand left suspending portions 42 respectively, a number and anarrangement of the roller rows are optional.

For example, as shown in FIGS. 6 and 7, the device may have a structurehaving four rows of rollers in total of which right and left two rows ofrollers are disposed between the right and left side surfaces of thetrack rail 2 and the inner side surfaces of the right and leftsuspending portions 42 of the block body 40, respectively.

FIG. 6 shows an example having a structure in which the upper row ofrollers 3 among the two rows of the rollers 3 arranged vertically isformed so that a contact angle line L1 of the roller 3 is set toobliquely extend upwards from a side of the track rail 2 to the rightand left suspending portions 42 of the block body 40 and is formed so asto incline with an inclination angle of almost 45° with respect to ahorizontal line H, while the lower row of rollers 3 is formed so that acontact angle line L2 of the roller 3 is set to obliquely extenddownwards, and is formed so as to incline with an inclination angle ofalmost 45°.

FIG. 7 shows an example having a structure in which the upper row ofrollers 3 among the two rows of the rollers 3 arranged vertically isformed so that a contact angle line L1 of the roller 3 is set toobliquely extend downwards from a side of the track rail to sides of theright and left suspending portions 42, 42 of the block body 40 and isformed so as to incline with an inclination angle of almost 45° withrespect to a horizontal line, while the lower row of rollers 3 is formedso that a contact angle line L2 of the roller 3 is set to obliquelyextend upwards, and is formed so as to incline with an inclination angleof almost 45°.

In the case of this embodiment, the direction changing passages 10A, 10Bof vertically arranged two rows of rollers 3 disposed to both endportions of the block body 40 are arranged alternately with apredetermined interval in an axial direction so as to intersect to eachother. In this case, the direction changing passage inner peripheralportion forming member 12 formed to the end surface of the block body 40is provided with the direction changing passage inner periphery portion10 b of the direction changing passage 10A of a side close to the blockbody 40 and the direction changing roller end surface guide wall 10 c,the inner periphery portion 10 b and the guide wall 10 c beingintegrally molded with the block body 40.

As to the direction changing passage 10B far from H the block body 40,at least one portion of the loaded roller rolling surfaces 7, 8 of anend surface side of the block body 40, the direction changing passageinner periphery portion 10 b of a part which is connected to an endportion of the roller returning passage 9 and the direction changingroller end surface guide wall 10 c are integrally molded with the blockbody 40. While, a round piece 10C formed with the direction changingpassage inner periphery portion 10 b is attached to a part far from thedirection changing passage 10A. An inner periphery of this round piece10C is formed with a part of an outer periphery guide portion of theinside direction changing passage 10A. The side cover 11 is formed withthe direction changing passage outer peripheral portions 10 a, 10 a forboth the direction changing passages 10A, 10B arranged vertically.

According to the first invention described above. the assembling of theroller end surface guide wall, the roller returning passage and thedirection changing passage inner periphery portion is not required, thuseliminating the assembling process for the members.

In addition, the roller end surface guide wall, the roller returningpassage and the direction changing passage inner periphery portion canbe formed at accurate positions with respect to the block body.

When the direction changing passage inner periphery portion isintegrally formed with the block body, it becomes possible to eliminatethe irregularities to be formed at the connected portion between theroller rolling surface and the direction changing passage innerperiphery portion. In addition, as to the roller returning passage, whenit is integrally formed with the block body, it also becomes possible toeliminate the irregularities to be formed at the connected portionbetween the roller rolling changing passage inner periphery portion andthe roller returning passage.

Further, when the roller returning passage and the direction changingpassage inner peripheral portion are provided with guide walls forguiding the end surface of the roller, the guide wall being continuousto the roller end surface guide wall, and the roller returning passage.the roller end surface guide wall of at least one the paired roller endsurface guide walls and the direction changing passage inner peripheralportion are integrally formed with the block body, so that the rollerreturning passage, the guide walls of the direction changing passageinner periphery portions and the roller end surface guide walls can becontinuously molded, whereby irregularities are not formed at theconnected portions, thus enabling the end surface of the roller tosmoothly move.

In addition, the guide walls for the roller end surfaces can beintegrally formed in continuous in all around the endless circulatingpassage and a gap between the guide wall and the end surface of theroller can be formed with a high accuracy, so that the skew of theroller can be securely prevented.

In addition, when the engaging projection for preventing the roller fromfalling out by engaging with the chamfered portion of the roller isprovided at the roller end surface guide wall to be integrally moldedwith the block body, the engaging projection can be accuratelypositioned with respect to the block body, so that the falling-out ofthe roller can be surely prevented even if the bearing blocks isdetached from the track rail. In addition, there is no fear ofinterference of the block body with the roller during the circulation ofthe roller.

In addition, at a time of an insert molding, when a block supportingportion having a shape obtained by cutting an outer peripheral portionof the roller with a cross section passing through a center axis of theroller is provided to an inner periphery of a molding die so as tocorrespond to the roller rolling surface of the block body and the blockbody is positioned in the molding die by contacting the roller rollingsurface to the block supporting portion, the burr would not occur at theroller rolling surfaces.

In particular, when the paired right and left roller rolling surfaces ofthe block body are supported by the block supporting portions of themolding die, the block body is clamped from every four directions andsupported by the paired right and left block supporting portions at fourpoints. Therefore, even if an injection pressure of a molding materialis applied to the block body from every directions, the block body canbe held unmoved, and the block body can be accurately positioned.

[Second Invention]

Next, an embodiment of a second invention will be explained hereunderwith reference to the accompanying drawings.

FIGS. 8 and 9 disclose embodiments of linear roller guide devicesaccording to the second invention, respectively.

The linear roller guide device 201 comprises a track rail 202 and amovable block 204 assembled to be movable on an upper surface of thetrack rail 202 through four rows of rollers 203 in total of which tworows of rollers are disposed on an upper surface side of the track rail202 and one row of rollers is disposed on the right and left sidesurface sides of the track rail 202, respectively.

Each of the four rows of the rollers 203 circulates in an endlesscirculating passage constituted by the loaded area between the rollerrolling surfaces 206, 207; 205, 208 of the block body 2040 andcorresponding to the track rail 202, the direction changing passage 210and the roller returning passage 209. In this regard, the embodiment ofthis second invention is different form that of the first invention in apoint where the rollers 203 are linked to each other by a roller chain218 inserted to be movable in the endless circulating passage.

The roller chain 218 is a resin molded product, as shown in FIGS.9(c)-(e), and comprises spacer portions 218 a disposed between theadjacent rollers 203 and connecting bands (plates) 218 b as connectingmembers for connecting the respective spacer portions 218 a, theconnecting bands 218 b being flexible and having a thin plate-shape.

Both side surfaces of the spacer portion 218 is provided with aretaining recessed portion 218 c for constituting the falling-outpreventing portion having a circular-arc shape corresponding to acylindrical surface of the roller 203. The connecting plates 218 b arepositioned on a virtual surface connecting the center axes of therespective rollers 203.

The spacer portion 218 a is a member having a rectangular parallelepipedshape and a predetermined thickness so as to be disposed between therollers 203 and has almost the same length in axial direction as that ofthe roller 203 and a width shorter than a diameter of the roller 203. Inaddition, side surfaces in a thickness direction of the spacer portion218 a to which the roller 203 contacts are formed with retainingrecessed portions 218 c having a circular-arc shape corresponding to theshape of the roller 203.

Both side end portions in axial direction of the roller of theconnecting band 218 b of the roller chain 218 project from the endsurfaces of the roller in axial direction of the roller thereby to formguide projecting portions 2181.

Each of the rollers 203 is retained from back and forth in an arrangingdirection by the respective spacer portions 218 a of the roller chain218, so that it becomes unnecessary to form the chamfered portion to theend portion of the roller. As a result, a load can be supported by anentire length of the roller 203, and an effective length of the roller203 for bearing the load can be increased.

Furthermore, since only the spacer portion 218 a is disposed between theadjacent rollers 203, a pitch of the rollers 203 can be formed as smallas possible, so that a number of the rollers 203 to be disposed per unitlength for bearing the load can be increased as many as possible, thusimproving the load bearing ability of the roller 203.

FIG. 10(a) shows an example of the roller chain 218 of a case where theroller 2031 has a hollow structure having a penetration bore 2032. Inthe case of the roller 203 having the hollow structure, a pre-load canbe easily applied in comparison with a case of a solid roller 203, thusresulting in advantage.

A shaft portion 218 d to be inserted into the penetration bore 2032 isformed to the roller chain 218, whereby the roller chain 218 isintegrated with the roller 203. According to the structure describedabove, the falling-out of the roller 203 can be securely prevented, andthe degree of parallelization between the respective rollers 203 can beaccurately maintained.

FIG. 10(b) shows an example of the roller chain 218 of a case where theroller 2034 has a structure having recessed portions 2033 at its bothends.

The roller chain 218 is provided with convex portions 218 e to berotatively inserted into the recessed portions 2033 formed to both theend portions of the roller 203. According to this structure, thefalling-out of the roller 2034 can be surely prevented, and the degreeof parallelization between the respective rollers 2034 can be accuratelymaintained.

FIG. 10(c) shows an example of the roller chain 218 of a case where theroller 2036 has a structure having a circular groove 2035 at a center ofouter periphery of the roller 2036.

The roller 203 is retained by fitting a ring member 218f formed to theroller chain 218 into the circular groove 2035 of the roller chain 218.

On the other hand. FIG. 10(d) shows an example of the roller chain 218of a case where the connecting plate 218 b of the roller chain 218 isreinforced. Namely, the roller 218 is moved in the endless circulatingpassage having a track shape in accordance with the movement of themovable block 204, and the roller chain 218 is repeatedly subjected todeformations from a linear-shape to a curved-shape, so that it isrequired to increase a fatigue strength of the roller chain 218.

In view of this point, it is preferable to reinforce the connectingplate 218 b for linking the roller 203 by inserting reinforcing members218 g such as wire, thin plate or the like into the connecting plate 218b.

The track rail 202 is an elongated member formed to have a rectangularshape in section, an upper portion of both the side surfaces of thetrack rail being formed to have tapered surfaces which gradually expandoutwardly in upward direction, and each of the right and left taperedsurfaces is provided with one row of roller rolling surface 205,respectively. In addition, the upper surface of the track rail 202 isformed to be a plain surface of which both right and left end portionsare provided with one row of roller rolling surface 206, respectively,i.e., two rows of the roller rolling surfaces 206 in total.

The movable block 204 comprises a block body 2040 formed of metal, andside covers 211 to be attached to both end surfaces of the block body2040.

The block body 2040 has a U-shaped cross section and high rigidity andcomprises a horizontal portion 2041 opposing to the upper surface of thetrack rail 202, a pair of suspending portions 2042, 2042 suspending fromthe right and left end portions of the horizontal portion 2041 so as toclamp both the right and left side surfaces of the track rail 202. Alower surface of the horizontal portion 2041 is provided with a pair ofroller rolling surfaces 207, 207 corresponding to the paired rollerrolling surfaces 206, 206 formed to the upper surface of the track rail202, while each of inner side surfaces of the right and left suspendingportions 2042, 2042 is provided with roller rolling surface 208, 208corresponding to the respective roller rolling surfaces 205, 205 formedto the right and left side surfaces of the track rail 202.

A number of rollers 203 are disposed between four pairs of rollerrolling surfaces 205, 208; 206, 207 corresponding to each other, thatare formed to opposing surfaces between the track rail 202 and themovable block 204, whereby roller rows for bearing a load to be appliedto portions between the track rail 202 and the movable block 204 areassembled. A predetermined pre-load is applied to respective rollers203.

Each of the rollers 203 linearly contacts to the roller rolling surfaces205, 208; 206, 207. A contact angle a line L1 constituted by a lineconnecting two contact portions of the roller disposed between thecorresponding roller rolling surfaces 205, 208; 206, 207 formed to theupper surface of the track rail 202 and the horizontal portion 2041 ofthe block body 2040 is set to vertically extend with an inclinationangle of about 90° with respect to a horizontal line passing through acenter of the roller 203, while a contact angle line of the roller 203disposed between the corresponding to the roller rolling surfaces formedto the right and left side surfaces of the track rail 202 and the insidesurfaces of the right and left suspending portions 2042, 2042 of theblock body 2040 is set to obliquely extend toward a center of the trackrail 202 and is formed so as to upwardly incline with a predeterminedangle of α with respect to a horizontal line H passing through a centerof the roller 203, thereby to form a structure in which both the rightand left corner portions 2022, 2022 of an upper portion of the trackrail 202 are clamped by the two rows of rollers 203, 203 disposed to theright and left sides of the track rail 202 and by the two rows ofrollers 203, 203 disposed to the upper surface side of the track rail202. In the embodiment shown in Figure, the inclination angle of α isset to about 30°.

The block body 2040 is provided with four rows of the roller returningpassages 209 for circulating and guiding the four rows of rollers 203.The roller returning passage 209 linearly extend in parallel to therespective roller rolling surfaces 205, 206 formed to the block body2040. Two rows of the roller returning passages 209 are provided to thehorizontal portion 2041, while two rows of the roller returning passages209 are respectively provided to the right and left suspending portions2042 of the block body 2040. The roller returning passage 209 is formedof a roller returning passage forming member 2091 composed of resin.

The roller returning passage forming member 2091 is integrally bonded toan inner peripheral portion of a penetration bore 2043 penetratingthrough the horizontal portion 2041 and the suspending portion 2042 ofthe block body 2040. An outer peripheral shape of the roller returningpassage forming member 2091 is formed to have a cylindrical shape whichconforms to an inner peripheral shape of the penetration bore 2041. Theinner periphery of the roller returning passage forming member 2091 isprovided with a roller returning passage 209 having a rectangular crosssection for guiding the roller 203.

The roller returning passage 209 comprises a pair of unloaded rollerguide surfaces 209 a, 209 b extending in parallel to each other forguiding a cylindrical outer periphery surface of the roller 203, and apair of unloaded roller end surface guide surfaces 209 c, 209 cextending in parallel to each other for guiding end surfaces of theroller 203.

A gap or clearance between the paired unloaded roller guide surfaces 209a, 209 b is set to slightly larger than a diameter of the roller 203 soas to form a small gap therebetween, while a gap or clearance betweenthe paired roller end surface guide walls 209 c, 209 c is set toslightly larger than a length of the roller 203 so as to form a smallgap therebetween, thus resulting in a structure enabling to smoothlymove the rollers 3.

The unloaded roller end surface guide walls 209 c, 209 c are formed withguide grooves 209 d with which the guide projecting portions 2181 of theroller chain 218 are engaged.

FIG. 11 shows another embodiment of a roller returning passage formingmember 2092 to be formed to the suspending portion 2042 of the blockbody 2040. Namely, the roller returning passage forming member 2092 isintegrally bonded to a recessed portion 2044 formed to a lower endportion of the right and left suspending portions 2042 of the block body2040. The roller returning passage forming member 2091 is integrallyconnected to a third loaded roller end surface guide wall forming member2143 provided to the inner peripheral side of the suspending portion2042.

According to the structure described above, the block body 2040 isrequired to be provided with only two penetration bores 2043 to beformed to the horizontal portion 2041, thus making simple themanufacturing of the device.

In addition, as shown in FIGS. 8, 9(a) and 9(b) both end portions of theblock body 2040 are provided with side covers 211 constituting adirection changing passage 210 for changing the rolling direction of theroller 203 to the roller returning passage 209, the roller 203 beingdisposed between the loaded roller rolling surfaces 205, 208; 206, 207formed to the track rail 202 and the block body 2040.

The direction changing passage 210 is formed to be a pipe having aU-shape. The side cover 211 is formed with only a direction changingpassage inner periphery portion 210 a of the direction changing passage210, while a direction changing passage inner periphery portion formingmember 212 is integrally bonded to both end portions of the block body2040.

This direction changing passage 210 has a rectangular shaped crosssection, and both side portions of the direction changing passage outerperiphery portion 210 a and the inner periphery portion 210 b forguiding the outer periphery surface of the roller 203 are provided withdirection changing roller end surface guide walls 210 c, 210 c forguiding the end surfaces of the roller 203. This direction changingroller end surface guide walls 210 c together with the directionchanging passage inner periphery portion 210 b are formed to thedirection changing passage inner periphery portion forming member 212.Then, when the side cover 211 formed with the direction changing passageouter periphery portion 210 a is fitted into the end surface of theblock body 2040 formed with the direction changing passage innerperiphery portion 210 b and the direction changing roller end surfaceguide walls 210 c, the direction changing passage 210 having a U pipeshape is formed.

The direction changing roller end surface guide walls 210 c, 210 c areformed with guide grooves 210 d with which the guide projecting portions2181 of the roller chain 218 are engaged.

In this regard, the direction changing roller end surface guide walls210 c, 210 c together with the direction changing passage outerperiphery portion 210 a may be provided to the side cover 211. Inanother way, one direction changing roller end surface guide wall 210 ctogether with the direction changing passage inner periphery portion 210b may be provided to a side of the direction changing passage innerperiphery portion forming member 212, while the other direction changingroller end surface guide walls 210 c together with the directionchanging passage outer periphery portion 210 a may be provided to theside cover 211.

In still another way, the direction changing roller end surface guidewall 210 c is divided into two portions i.e., an inner periphery sideportion and an outer periphery side portion, and then, the outerperiphery side portion may be formed to the side cover 211, while theinner periphery side portion may be provided to the direction changingpassage inner periphery portion forming member 212.

Further, as shown in FIG. 8(a) along the respective four rows of rollerrolling surfaces 207, 208 of the block body 240, there is provided witha loaded roller end surface guide wall 213 for guiding the end surfacesof the roller in the loaded area.

The loaded roller end surface guide walls 213 are formed with guidegrooves 213 a with which the guide projecting portions 2181 of theroller chain 218 are engaged. In order to form the loaded roller endsurface guide wall 213, the block body 240 comprises a first end surfaceguide wall forming member 2141 to be integrally bonded to a lowersurface of the horizontal portion 2040, the right and left second endsurface guide wall forming members 2142 to be integrally bonded torecessed corner portions between the horizontal portion 2041 and theright and left suspending portions 2042, and right and left third endsurface guide wall forming members 2143 to be integrally bonded to alower portion of inner side surface of the right and left suspendingportions 2042.

Both the end portions of the first end surface guide wall forming member2141 and an upper end portion of the second end surface guide wallforming members 2142 are provided with loaded roller end surface guidewalls 213, 213; 213, 213 for guiding the end surfaces of the roller 203rolling on the roller rolling surfaces 207, 207 formed to the lowersurface of the horizontal portion 2041 of the block body 2040.

In addition, the lower end portions of the right and left second endsurface guide wall forming members 2142 and an upper end portion of thethird end surface guide wall forming members 2143 are provided withloaded roller end surface guide walls 213, 213; 213, 213 for guiding theend surfaces of the roller 203 rolling on the roller rolling surfaces208, 208 formed to the suspending portion 2042 of the block body 2040.

A gap or clearance between the paired loaded roller end surface guidewalls 213, 213 is set to slightly larger than a length of the roller 203so as to form a small gap between the end surface of the roller 203 andthe guide wall 213.

Further, a first seal member 216 for sealing the gap formed between thehorizontal portion 2041 of the block body 2040 and the upper surface ofthe track rail 202 is attached to the first end surface guide wallforming member 2141, while a second seal member 217 for sealing the gapformed between the suspending portion 2042 of the block body 2040 andthe right and left side surfaces of the track rail 202 is attached tothe third end surface guide wall forming member 2143.

In this embodiment, the loaded roller end surface guide walls 213 forguiding both end surfaces of the roller 203 is formed by the first tothird end surface guide wall forming members 2141-2143 that are allcomposed of resin.

However, as shown in FIG. 11(a), the loaded roller end surface guidewalls 213 for guiding one end surface of the roller 203 may be formed bythe block body 2040 per se, while the loaded roller end surface guidewall 213 for guiding the other end surface of the roller 203 may beformed by the loaded roller end surface guide wall forming member 214.In this case, the loaded roller end surface guide walls 213 may beformed with guide grooves with which the guide projecting portions 2181of the roller chain 218 are engaged. In another way, as shown in FIG.11(b), a cutout 213 b can be also formed in place of the guide groove.

In this second embodiment, all of the roller returning passage formingmember 2091, the roller end surface guide wall forming members 2141-2143and the direction changing passage inner periphery portion formingmember 212 is formed by integrally molding with the movable block 2040.

Accordingly, the unloaded roller guide surfaces 209 a, 209 b of theroller returning passage 209 and both the inner and outer peripheryportions 210 a, 210 b of the direction changing passage can becontinuously and integrally molded. Further, the direction changingpassage inner periphery portion 210 b and the roller rolling surfaces207, 208 in the loaded area can be also integrally molded.

In addition, the roller end surface guide wall 209 c of the rollerreturning passage 209, the direction changing roller end surface guidewall 210 c of the direction changing passage 210 and the loaded arearoller end surface guide wall 213 are continuously formed by beingintegrally molded, so that the roller end surface guide wall can becontinuously formed in all around the endless circulating passage. Inaddition, the guide groove for engaging with the guide projectingportion 2181 of the roller chain 218 can be continuously formed in allaround the endless circulating passage.

According to the linear roller guide device of this invention, theroller returning passage forming member 2091 and the direction changingpassage inner periphery portion forming member 212 are not required,thus enabling to omit the assembling process for the members. Inaddition, the roller returning passage 209 and the direction changingpassage inner periphery portion 210 a can be provided at accuratepositions with respect to the block body 2040.

When the direction changing passage inner periphery portion formingmember 212 is integrally formed with the block body 2040, it becomespossible to eliminate the irregularities to be formed at the connectedportion between the roller rolling surfaces 207, 208 and the directionchanging passage inner periphery portion 210 b. In addition, as to theroller returning passage 209, when the member 91 is integrally formedwith the block body 2040, it becomes also possible to eliminate theirregularities to be formed at the connected portion between thedirection changing passage inner periphery portion 210 b and theunloaded roller guide surface 209 b of the roller returning passage 209.

On the other hand, the rollers 203 can be smoothly rolled and moved fromthe roller returning passage 209 in the unloaded area and the directionchanging passage 210 to the loaded area between the roller rollingsurfaces 206, 207; 205, 208 while being held in a state where the centeraxes of the respective rollers 203 are retained in parallel to eachother and intervals of adjacent rollers 203 are retained in apredetermined distance by the roller chain 218.

In particular, when the roller chain 218 is circulated and moved, theguide projecting portions 218 a formed to the roller chain 218 areguided in all around the circulating passage by the guide grooves 209 d,210 d and 213 a formed to the guide walls 213 provided to both sides ofthe roller returning passage 209, the direction changing inner peripheryportion 210 b and the roller rolling surfaces 207, 208, so that therun-out of the roller chain 218 during the circulation can be suppressedin all around the circulating passage. Accordingly, the roller chain 218can circulate and move on a predetermined track in all around theendless circulating passage. As a result, the rollers 203 can accuratelyroll and move, thus preventing the skew-generation of the rollers 203.

Furthermore, in this embodiment, the gaps between the guide walls 213,the direction changing roller end surface guide wall 210 c in the loadedarea and the unloaded roller end surface guide wall 209 c and the rollerend surfaces can be accurately maintained to a predetermined value, sothat the gap can be reduced to a sufficiently small value. As a result,the skew of the rollers 203 can be securely prevented in cooperationwith the retaining function of the roller chain 218.

Furthermore, when the movable block 204 is detached from the track rail202, the rollers 203 are retained by the roller chain 218.

The integrally molding of the roller returning passage forming member2091, the direction changing passage inner peripheral portion formingmember 212 and the loaded roller end surface guide wall 213 with theblock body 2040 is performed in accordance with an insert molding methodcomprising the steps of disposing the block body 2040 into a molding die215 on the basis of the roller rolling surfaces 207, 208 formed to theblock body 2040, forming cavities corresponding to the respective resinmolded portions to be formed between an inner wall of the molding die215 and the block body 2040, and injecting a molding material into thecavities to form the resin molded portions.

FIG. 12 is a schematic view showing the block body 2040 and states wherethe molding dies 215 are clamped or opened at the time of the insertmolding. Namely, a fixed molding die 215 a is provided with blocksupporting portions 215 b to which the roller rolling surfaces 207, 207;208, 208 are fitted for positioning, while a movable molding die 215 cis provided with pins 215 d for forming the roller returning passage.The block supporting portions 215 b and the pins 215 d are formed withprojecting portions 215 b 1, 215 d 1 corresponding to the guideprojecting portion 2181 of the roller chain 218.

The block supporting portions 215 b have plain shapes corresponding tothe roller rolling surfaces 207, 207: 208, 208 and linearly extend inparallel to each other. In this regard, FIGS. 12(b) and 12(c) shows onlya circumference of the roller returning passage 209 of a side of thesuspending portion 2042.

Cavities 215 d for forming the roller returning passage forming member2091 are provided inside the penetration bores 2043 formed in thehorizontal portion 2041 and the suspending portion 2042 of the blockbody 2040, respectively. Further, cavities 215 e for forming the firstto third loaded roller end surface guide wall forming members 213 areprovided to inner periphery portions of the horizontal portion 2041 andthe suspending portion 2042, respectively. Furthermore, cavities 215 ffor forming the direction changing passage inner periphery portionforming members 212 are provided to both front and back end portions ofthe block body 2040, respectively.

In this embodiment, the paired right and left roller rolling surfaces207, 207; 208, 208 of the block body 2040 are supported at four pointsby the block supporting portions 215 b of the molding die 215. As aresult, the block body 2040 can be supported unmoved by the blocksupporting portions 215 b, even if an injection pressure of a moldingmaterial is applied to the block body 2040 from every directions,whereby the roller returning passage 209, the direction changing innerperiphery portion 210 b and the first to third loaded roller end surfaceguide walls 2131-2133 can be accurately formed at predeterminedpositions.

In addition, since the block body 2040 is stably positioned in themolding die 215, the burr is not formed at portions between the rollerrolling surfaces 207, 207; 208, 208.

It is preferable that the block supporting portions 215 b closelycontact to the roller rolling surfaces 207, 208. However, even the blocksupporting portions 215 b and the roller rolling surfaces 207, 208 aremoved in a small distance due to a small gap formed therebetween, thesmall gap shall be allowed as far as a dimension accuracy is within anallowable range and the resin material would not penetrate through thegap.

[Modifications of Roller Contact Angles]

Though the explanation described above has been made by taking intoconsideration an example of a case in which total four rows of rollersare disposed between corresponding portions i.e., the right and left tworows of rollers being disposed between the upper surface of the trackrail 202 and the lower surface of the horizontal portion 2041 of theblock body 2040 while one row of rollers being disposed between theright and left side surfaces of the track rail 202 and the inner sidesurfaces of the right and left suspending portions 2042 respectively, anumber and an arrangement of the roller rows are optional.

For example, as shown in FIGS. 13 and 14, the device may have astructure having four rows of rollers in total in which right and lefttwo rows of rollers are disposed between the right and left sidesurfaces of the track rail 202 and the inner side surfaces of the rightand left suspending portions 2042 of the block body 2040, respectively.

FIG. 13 shows an example having a structure in which the upper row ofrollers 203 among the two rows of the rollers 203 arranged vertically isformed so that a contact angle line of the roller 203 is set toobliquely extend upwards from a side of the track rail 202 to the rightand left suspending portions 2042 of the block body 2040 and is formedso as to incline with an inclination angle of almost 45° with respect toa horizontal line, while the lower row of rollers 203 is formed so thata contact angle line of the roller 203 is set to obliquely extenddownwards and is formed so as to incline with an inclination angle ofalmost 45°.

FIG. 14 shows an example having a structure in which the upper row ofrollers 203 among the two rows of the rollers 203 arranged vertically isformed so that a contact angle line L1 of the roller 203 is set toobliquely extend downwards from a side of the track rail to sides of theright and left suspending portions 2042, 2042 of the block body 2040 andis formed so as to incline with an inclination angle of almost 45° withrespect to a horizontal line H, while the lower row of rollers 203 isformed so that a contact angle line L2 of the roller 203 is set toobliquely extend upwards and is formed so as to incline with aninclination angle of almost 45°.

In the case of this embodiment, the direction changing passages 210A,210B of vertically arranged two rows of rollers 3 disposed to both endportions of the block body 2040 are arranged alternately with apredetermined interval in an axial direction so as to intersect to eachother. In this case, the direction changing passage inner peripheralportion forming member 212 formed to the end surface of the block body2040 is provided with the direction changing passage inner peripheryportion 210 b of the direction changing passage 210A of a side close tothe block body 2040 and the direction changing roller end surface guidewall 210 c, the inner periphery portion 210 b and the guide wall 210 cbeing integrally molded with the block body 2040.

As to the direction changing passage 210B far from the block body 2040,at least one portion of the loaded roller rolling surfaces 207, 208 ofan end surface side of the block body 2040, the direction changingpassage inner periphery portion 210 b of a part which is connected to anend portion of the roller returning passage 209 and the directionchanging roller end surface guide wall 210 c are integrally molded withthe block body 2040. While, a round piece 210C formed with the directionchanging passage inner periphery portion 210 b is attached to a part farfrom the direction changing passage 210A. An inner periphery of thisround piece 210C is formed with a part of an outer periphery guideportion of the inside direction changing passage 210A. The side cover211 is formed with the direction changing passage outer peripheralportions 210 a, 210 a for both the direction changing passages 210A,210B arranged vertically.

According to the second invention described above, since the rollers arecirculated in a state of being retained by the roller chain, the rollersare rolled and moved in a state where center axes of the respectiverollers are retained in parallel to each other by the roller chain.Therefore, the generation of skew can be prevented and the rollers canbe smoothly rolled and moved,

In addition, since the roller chain is guided on a predetermined trackthrough the roller chain guide portions formed to the roller returningpassage and the direction changing passage, the rollers retained by theroller chain can be also accurately guided.

In addition, the running-out of the roller chain can be prevented by theroller chain guide portions.

In particular, when the roller returning passage to be formed with theroller chain guide portions, the roller returning passage forming memberto be formed with the direction changing inner periphery portion and thedirection changing passage inner periphery portion forming member areintegrally molded with the block body, the roller chain guide portionscan be accurately formed on the track.

In addition, when the direction changing passage inner periphery portionforming member is integrally formed with the block body, it becomespossible to eliminate the irregularities to be formed at the connectedportion between the roller rolling surface and the direction changingpassage inner periphery portion. In addition, as to the roller returningpassage, when it is integrally formed with the block body, it alsobecomes possible to eliminate the irregularities to be formed at theconnected portion between the direction changing passage inner peripheryportion and the roller returning passage, whereby the rollers can befurther smoothly circulated and moved in cooperation with the guidingfunction of the roller chain.

Furthermore, when the roller chain is formed so as to have an endlessstructure and is provided with a falling-out preventing portion for therollers, the falling-out of the rollers can be prevented by the rollerchain even if the movable block is detached from the track rail.

In addition, the roller chain is provided with a guide projectingportion, while the roller returning passage and the direction changingpassage inner peripheral portion are provided with guide grooves. Inaddition, a side of the roller rolling surface in the loaded area isprovided with a guide wall having the guide groove, and the guide wallis integrally molded with the block body by using an insert moldingmethod, so that the roller chain can be accurately guided in all aroundthe endless circulating passage, thus enabling the rollers to furthersmoothly circulate and move.

According to the structure described above, when the roller chain iscirculated and moved, the guide projecting portion is engaged with theguide groove formed to the roller returning passage and the directionchanging passage inner peripheral portion, so that the run-out of theroller chain during the circulation is suppressed. As a result, therollers can be rolled and moved in orderly arranged state in all aroundthe endless circulating passage.

In addition, in a case where the roller chain is formed in astriped-shape having no connected portion at both ends thereof, when themovable block is detached from the track rail, the guide projectingportion is engaged with the guide groove, thus enabling to prevent asagging or slack of an end portion of the roller chain. Further, a alsoin the case of the roller chain having an endless structure, the saggingor slack of an intermediate portion of the roller chain can beprevented.

When the roller chain comprises spacer portions disposed between theadjacent rollers and connecting members for connecting the respectivespacer portions, each of the rollers is arranged and circulated in astate where the rollers are retained by the spacer portions from backand forth in the arranging direction thereof.

Further, when a falling-out preventing portion for the roller isprovided to the spacer portion so as to prevent the roller falling-outfrom back and forth of the roller, it becomes unnecessary to chamfer theend portion of the roller, so that an effective length of the roller forbearing the load can be increased, thus enabling to improve the loadbearing ability.

Furthermore, since only the spacer portion is disposed between theadjacent rollers, a pitch of the rollers can be formed as small aspossible, so that a number of the rollers required to be disposed perunit length for bearing the load can be increased as many as possible,thus further improving the load bearing ability of the roller.

In addition, when the roller is formed to have a hollow structure andthe roller is retained by inserting a resin portion into the hollowportion of the roller, the falling-out of the roller can be securelyprevented and a degree of parallelization between the adjacent rollerscan be accurately maintained.

In addition, as an example of a case where the hollow portion does notpenetrate, the roller may be retained in such a manner that a recessedportion is formed to both end portions of the roller and the resinportion is inserted into the recessed portion or in a manner that agrooved portion is formed to a center peripheral portion of the rollerand the resin portion is fitted into the grooved portion.

In addition, when the roller chain is reinforced by inserting a wire orthin plate into the connecting member for linking the rollers, a fatiguestrength and life duration of the roller chain can be increased.

In addition, at a time of the insert molding, when a block supportingportion having a shape obtained by cutting an outer peripheral portionof the roller with a cross section passing through a center axis of theroller is provided to an inner periphery of a molding die so as tocorrespond to the roller rolling surface of the block body, and theblock body is positioned in the molding die by contacting the rollerrolling surface to the block supporting portion, the burr would notoccur at the roller rolling surfaces.

In particular, when the paired right and left roller rolling surfaces ofthe block body are supported by the block supporting portions of themolding die, the block body is clamped from every four directions andsupported by the paired right and left block supporting portions at fourpoints. Therefore, even if an injection pressure of a molding materialis applied to the block body from every directions, the block body canbe held unmoved, thus the block body can be accurately positioned.

INDUSTRIAL APPLICABILITY

As described above, the linear roller guide device according to thepresent invention is widely applicable to linear guide mechanisms forvarious industrial equipments such as machine tool, robot operatingsystem, measuring apparatus or the like.

What is claimed is:
 1. A linear roller guide device comprising a trackrail and a movable block assembled to the track rail through a number ofrollers, said movable block comprising: a roller rolling surface onwhich said rollers roll; a block body having a roller returning passagecorresponding to the roller rolling surface; a direction changingpassage inner periphery portion formed to both end surfaces of the blockbody; a pair of roller end surface guide walls formed to both sides ofthe roller rolling surface of the block body and adapted to guide boththe end surfaces of the roller; and side covers each having a directionchanging passage outer periphery portion for forming a directionchanging passage by fitting the side cover into the direction changingpassage inner periphery portion formed to both end surfaces of the blockbody, said track rail including a roller rolling surface extending in anaxial direction corresponding to the roller rolling surface of the blockbody, and said rollers circulating in an endless circulating passageconstituted by a loaded area between the roller rolling surface of theblock body and the roller rolling surface corresponding to the trackrail, the direction changing passage and the roller returning passage,wherein at least one of a roller returning passage forming member forforming the roller returning passage, which is of one-piece constructionwith a guide wall guiding a roller end surface, a direction changingpassage inner periphery portion forming member for forming the directionchanging passage inner periphery portion, which is of one-piececonstruction with the guide wall and a roller end surface guide wallforming member for forming at least one of the paired roller end surfaceguide walls, is formed as a molded body integrally formed with the blockbody by inserting the block body into a molding die.
 2. A linear rollerguide device according to claim 1, wherein said roller returning passageforming member and said direction changing passage inner peripheralportion forming member are provided with guide walls for guiding the endsurfaces of the rollers, the guide walls being continuous to the rollerend surface guide wall, and said roller returning passage formingmember, said roller end surface guide wall forming member of at leastone of the paired roller end surface guide wall forming members and saiddirection changing passage inner peripheral portion forming member areintegrally molded with the block body.
 3. A linear roller guide deviceaccording to any one of claims 1 and 2, wherein a block supportingportion having a shape obtained by cutting an outer peripheral portionof the roller with a cross section passing through a center axis of theroller is formed to an inner periphery of a molding die so as tocorrespond to the roller rolling surface of the block body at a time ofan insert molding, and the block body is positioned in the molding dieby contacting the roller rolling surface to the block supportingportion.
 4. A linear roller guide device according to any one of claims1, 2 and 6 wherein said device has a structure having four rows ofrollers in total in which a paired right and left rows of rollers aredisposed to be rollable between the upper surface of the track rail anda lower surface of a horizontal portion of the block body and two rowsof the rollers each is disposed between the right and left side surfacesof the track rail and inside surfaces of a suspending portion of theblock body, respectively.
 5. A linear roller guide device according toclaim 4, wherein a contact angle line constituted by a line connectingtwo contact points of said roller disposed between the roller rollingsurfaces formed to the upper surface of the track rail and thehorizontal portion of the block body is set to vertically extend with aninclination angle of approximately 90° with respect to a horizontalline, while a contact angle line of the roller disposed between theroller rolling surfaces formed to the right and left side surfaces ofthe track rail and the inside surfaces of the suspending portion of theblock body is set to obliquely extend downwards and is formed so as toincline with an inclination angle of approximately 30° with respect to ahorizontal line.
 6. A linear roller guide device according to claim 1,wherein said roller is provided with a chamfered portion formed to atleast one end portion of the roller, and an engaging projection withwhich said chamfered portion of the roller is engaged is provided at theroller end surface guide wall integrally molded with the block body soas to prevent the roller from falling-out.
 7. A linear roller guidedevice according to any one of claims 1, 2 and 6, wherein said guidedevice has a structure having four rows of rollers in total in which tworows of rollers are vertically disposed to be rollable at upper andlower portions between a right side surface of the track rail and aright inside surface of the suspending portion of the block body,respectively, while the remaining two rows of rollers are verticallydisposed to be rollable at upper and lower portions between a left sidesurface of the track rail and a left inside surface of the suspendingportion of the block body, respectively.
 8. A linear roller guide deviceaccording to claim 7, wherein said upper row of rollers is formed sothat a contact angle line of the roller is set to obliquely extendupwards from a side of the track rail to sides of the right and leftsuspending portions of the block body and is formed so as to inclinewith an inclination angle of approximately 45° with respect to ahorizontal line, while said lower row of rollers is formed so that acontact angle line of the roller is set to obliquely extend downwardsand is formed so as to incline with an inclination angle ofapproximately 45° with respect to a horizontal line.
 9. A linear rollerguide device according to claim 7, wherein said upper row of rollers isformed so that a contact angle line of the roller is set to obliquelyextend downwards from a side of the track rail to sides of the right andleft suspending portions of the block body, and is formed so as toincline with an inclination angle of approximately 45° with respect to ahorizontal line, while the lower row of rollers is formed so that acontact angle line of the roller is set to obliquely extend downwardsand is formed so as to incline with an inclination angle of almost 45°with respect to a horizontal line.